Fujitsu Services has kick started a 90-day consultation period with staff after sending 3,800 of them letters detailing proposals to close the final pension salary scheme.
This is in spite of a £177m profit the firm made in the last fiscal year and follows a series of cost cutting measures the integrator has taken in the last six months, including a payment freeze and 'out of hours' wages.
The UK's largest union Unite has condemned the proposals, arguing that in light of its financial health Fujitsu Services needed to re-consider its position.
"The company has yet to produce any proper justification for this latest attempt to rise profits by cutting pension benefits, and this action may hinder future bids for blue chip private sector outsourcing contracts," said National Officer Peter Skyte.
"We will be mounting a robust campaign to persuade the company to think again," he added.
The deficit accrued on Fujitsu Services' final salary pension scheme was £1bn, said a spokesman at the integrator, who added the money paid into the scheme was guaranteed but it would discontinue further payment.
"We anticipate staff will move onto the money purchase pension scheme," he told MicroScope.
"Whilst this action is regretted it is a prudent step to enable us to manage the pension risk. Consultation will begin on 15 May 2009 with the pension members committee and with Unite," he stated.